Setting Up, Configuring, and Using an Oracle WebLogic Server Cluster by Yuli Vasiliev

Learn to take advantage of multiple Oracle WebLogic Server instances
grouped into a cluster to maximize scalability and availability.

The
key characteristics of a successful online system today include high
availability, reliability, and scalability. Put simply, your online
system must be ready to process a user request quickly and at any time,
even when the number of requests grows abruptly. Strictly speaking, a
growing number of user requests is a good thing, because that makes it
clear that your online business is booming and opening up new
opportunities for you. The ability to act on opportunities is a key
characteristic of many successful businesses today.

To meet the
requirements for greater availability and scalability, more and more
companies are moving toward clustered infrastructures for their online
solutions. Oracle WebLogic Server supports clustering, allowing an
Oracle WebLogic Server cluster to be composed of multiple Oracle
WebLogic Server instances running on different servers at the same time,
so that application deployed to the cluster can take advantage of the
combined processing power of multiple servers, failover, and load
balancing.

To end users and applications, multiple Oracle WebLogic
Server instances grouped into a cluster appear as a single Oracle
WebLogic Server instance. But beneath the surface, the cluster uses an
infrastructure that enables interconnecting clustered Oracle WebLogic
Server instances to make them work as a single unit. It's important to
realize, though, that setting up and using that infrastructure involves
some configuration work on the part of a cluster administrator.

Key Benefits of ClusteringThe
idea behind clustering is pretty simple: Multiple server instances are
grouped to work together to achieve increased scalability and
reliability. In particular, the benefits of an Oracle WebLogic Server
cluster include the following:

High availability - You can
deploy your applications on multiple server instances within an Oracle
WebLogic Server cluster. In this case, if a server instance that is
running your application fails, application processing will continue
(transparently to the application users) on another instance.

Scalability
- New server instances can be dynamically added to a cluster to match
consumer demand, without interrupting application processing.

Improved
performance - Another advantage to deploying on multiple server
instances in a cluster is that it provides several alternatives for
application processing. The load balancing mechanism that clustering
enables can significantly improve performance of your clustered
application due to the efficient distribution of jobs and communications
across the resources within the cluster.